Systems, methods and apparatus configured to manage neighbor cell lists

ABSTRACT

According to some wireless network standards the size of a neighbor cell list is restricted to a maximum size. The limited size of a neighbor cell list may not reflect the realities of a wireless network deployment, especially for deployments including numerous femto cells clustered in close proximity. Accordingly, as the concentration of macro cells and/or femto cells in an area increases, there lies a challenge to identify and communicate neighbor lists to user devices that reflect the arrangement of a particular portion of the deployment and the needs of the user devices. Various systems, methods and apparatus described herein are configured to provide a user device or a group of user devices a neighbor cell list that includes neighbor cell identifiers chosen from a candidate list.

CLAIMS OF PRIORITY UNDER 35 U.S.C. §119

The present Application for Patent is a continuation of U.S. patentapplication Ser. No. 12/860,613, entitled “SYSTEMS, METHODS ANDAPPARATUS CONFIGURED TO MANAGE NEIGHBOR CELL LISTS,” filed Aug. 20,2010, which claims priority to U.S. Provisional Application No.61/236,014, entitled “EXPANSION OF NEIGHBOR CELL LISTS IN WIRELESSSYSTEMS VIA OPTIMAL ROTATION OF LIST MEMBERS,” filed Aug. 21, 2009. Theabove-referenced applications are hereby expressly incorporated byreference herein.

BACKGROUND

Field

The present application relates to wireless systems, and morespecifically to systems, methods and apparatus configured to manageneighbor cell lists in wireless systems.

Background

Wireless communication systems are widely deployed to provide varioustypes of communication (e.g., voice, data, multimedia services, etc.) tomultiple users. In addition to mobile phone networks currently in place,a new class of small base stations has emerged, which may be installedin a private or public spaces to provide wireless coverage to mobileunits using broadband Internet connections. These small base stationsare generally known as access point base stations, or, alternatively,Home Node B (HeNB or HNB) or femto nodes. Typically, femto nodes areconnected to the Internet and the mobile operator's network via a directsubscriber line (DSL) router or a cable modem. Femto nodes may bedeployed by individual users or groups within the coverage area of aconventional macro node or cell.

In order to enable user devices to transfer service from one basestation or access point to another, various wireless network standardsenable base stations and access points to provide deployment informationto user devices. Typically the deployment information is a list ofneighbor cell identifiers known as a neighbor cell list (or a neighborlist).

However, according to some wireless network standards, such as UniversalMobile Telecommunication System (UMTS) for example, the size of theneighbor list is restricted to a maximum size. That is, a base stationor access point can only include a preset number of neighbor cellidentifiers in the neighbor list at one time. The fixed size of aneighbor list provided by a standard may not reflect the realities of awireless network deployment, especially for deployments includingnumerous femto cells clustered in close proximity. In particular, thenumber of macro, pico and/or femto cells in one area may exceed themaximum size of the neighbor list as specified in a standard relevant tothe deployment. Accordingly, as the concentration of macro cells and/orfemto cells in an area increases, there lies a challenge to identify andcommunicate neighbor lists to user devices that reflect the arrangementof a particular portion of the deployment and the needs of the userdevices.

SUMMARY

Various embodiments of systems, methods and devices within the scope ofthe appended claims each have several aspects, no single one of which issolely responsible for the desirable attributes described herein.Without limiting the scope of the appended claims, some prominentfeatures are described herein. After considering this discussion, andparticularly after reading the section entitled “Detailed Description”one will understand how the features of various embodiments are used tomanage wireless network resources at base stations, pico nodes and/orfemto nodes.

One aspect of the disclosure is a method of forming a list ofneighboring wireless access points. In one embodiment, the methodincludes: determining a candidate list, the candidate list including aplurality of neighboring wireless access points, wherein each of theplurality of neighboring wireless access points has at least onecharacteristic by which that particular neighboring wireless accesspoint can be selected; and selecting at least one wireless access pointfrom the candidate list to form a neighbor list, the neighbor listincluding a subset of the plurality of neighboring wireless accesspoints included in the candidate list.

Another aspect of the disclosure is a wireless access point including:means for determining a candidate list, the candidate list including aplurality of neighboring wireless access points, wherein each of theplurality of neighboring wireless access points has at least onecharacteristic by which that particular neighboring wireless accesspoint can be selected; and means for selecting at least one wirelessaccess point from the candidate list to form a neighbor list, theneighbor list including a subset of the plurality of neighboringwireless access points included in the candidate list.

Another aspect of the disclosure is a wireless access point. In oneembodiment the wireless access point includes a controller configured toexecute code, and non-transitory computer readable memory storing codethat is executable by the controller. When executed by the controllerthe code is configured to: determine a candidate list, the candidatelist including a plurality of neighboring wireless access points,wherein each of the plurality of neighboring wireless access points hasat least one characteristic by which that particular neighboringwireless access point can be selected; and select at least one wirelessaccess point from the candidate list to form a neighbor list, theneighbor list including a subset of the plurality of neighboringwireless access points included in the candidate list.

Another aspect of the disclosure is a system including a controllerconfigured to execute code, and non-transitory computer readable memorystoring code. When executed by the controller the code is configured to:determine a candidate list, the candidate list including a plurality ofneighboring wireless access points, wherein each of the plurality ofneighboring wireless access points has at least one characteristic bywhich that particular neighboring wireless access point can be selected;and select at least one wireless access point from the candidate list toform a neighbor list, the neighbor list including a subset of theplurality of neighboring wireless access points included in thecandidate list.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a simplified block diagram of several sample aspects of acommunication system.

FIG. 2 is a flowchart illustrating a first method of forming a neighborcell list.

FIG. 3 is a flowchart illustrating a second method of forming a neighborcell list.

FIG. 4 is a flowchart illustrating a third method of forming a neighborcell list.

FIG. 5 is a flowchart illustrating a fourth method of forming a neighborcell list.

FIG. 6 is a flowchart illustrating a fifth method of forming a neighborcell list.

FIG. 7 is a flowchart illustrating a sixth method of forming a neighborcell list.

FIG. 8 is a flowchart illustrating a seventh method of forming aneighbor cell list.

FIG. 9 is a simplified diagram of a wireless communication system.

FIG. 10 is a simplified diagram of a wireless communication systemincluding femto nodes.

FIG. 11 is a simplified diagram illustrating coverage areas for wirelesscommunication.

FIG. 12 is a simplified block diagram of several sample aspects ofcommunication components.

FIGS. 13-23 are simplified block diagrams of several sample aspects ofapparatuses configured to provide provisioning and/or access managementas taught herein.

In accordance with common practice the various features illustrated inthe drawings may not be drawn to scale. Accordingly, the dimensions ofthe various features may be arbitrarily expanded or reduced for clarity.In addition, some of the drawings may not depict all of the componentsof a given system, method or device. Finally, like reference numeralsmay be used to denote like features throughout the specification andfigures.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

Various aspects of embodiments within the scope of the appended claimsare described below. It should be apparent that the aspects describedherein may be embodied in a wide variety of forms and that any specificstructure and/or function described herein is merely illustrative. Basedon the present disclosure one skilled in the art should appreciate thatan aspect described herein may be implemented independently of any otheraspects and that two or more of these aspects may be combined in variousways. For example, an apparatus may be implemented and/or a method maybe practiced using any number of the aspects set forth herein. Inaddition, such an apparatus may be implemented and/or such a method maybe practiced using other structure and/or functionality in addition toor other than one or more of the aspects set forth herein.

The techniques described herein may be used for various wirelesscommunication networks such as Code Division Multiple Access (CDMA)networks, Time Division Multiple Access (TDMA) networks, FrequencyDivision Multiple Access (FDMA) networks, Orthogonal FDMA (OFDMA)networks, Single-Carrier FDMA (SC-FDMA) networks, etc. The terms“networks” and “systems” are often used interchangeably.

In some aspects the teachings herein may be employed in a network thatincludes macro scale coverage (e.g., a large area cellular network suchas a 3G networks, typically referred to as a macro cell network) andsmaller scale coverage (e.g., a residence-based or building-basednetwork environment). As an access terminal (AT) or user equipment (UE)moves through such a network, the access terminal may be served incertain locations by access nodes (ANs) that provide macro coveragewhile the access terminal may be served at other locations by accessnodes that provide smaller scale coverage. In some aspects, the smallercoverage nodes may be used to provide incremental capacity growth,in-building coverage, outdoor coverage, and different services (e.g.,for a more robust user experience). In the discussion herein, a nodethat provides coverage over a relatively large area may be referred toas a macro node. A node that provides coverage over a relatively smallarea (e.g., a residence) may be referred to as a femto node. A node thatprovides coverage over an area that is smaller than a macro area andlarger than a femto area may be referred to as a pico node (e.g.,providing coverage within a commercial building).

A cell associated with a macro node, a femto node, or a pico node may bereferred to as a macro cell, a femto cell, or a pico cell, respectively.In some implementations, each cell may be further associated with (e.g.,divided into) one or more sectors.

Moreover, a particular femto node or group of femto nodes may onlypermit access to a particular group of users, known as a closedsubscriber group (CSG). Alternatively, other femto nodes, known as openaccess nodes, allow all users access without discrimination. There arealso hybrid-femto nodes that provide access to both CSG members andnon-members. However, hybrid-femto nodes discriminate between CSGmembers and non-members, and will terminate or deny system access tonon-members when CSG members are underserviced. Moreover, in somedeployments the three aforementioned distinctions also apply to piconodes and/or macro nodes.

In various applications, other terminology may be used to reference amacro node, a femto node, or a pico node. For example, a macro node maybe configured or referred to as an access node, base station, accesspoint, eNodeB, macro cell, and so on. Also, a femto node may beconfigured or referred to as a Home NodeB (HNB), Home eNodeB (HeNB),access point base station, femto cell, and so on. Analogous terminologyalso applies to pico nodes.

FIG. 1 is a simplified block diagram of several sample aspects of aportion of a communication system. The system 100 includes a basestation (or access point) 90 and a UE 120 (e.g. a smart phone, cellphone, computer, etc.). It should be appreciated, however, that thedescription herein may be applicable to other types of apparatus orother similar apparatuses that are referenced using other terminology.

Moreover, those skilled in the art will appreciate from the disclosureherein that a base station (or access point) includes a number offeatures not illustrated in FIG. 1, and for the sake of brevity, only asimplified set of features have been illustrated to discuss aspects ofembodiments disclosed herein. To that end, the base station 90 includes,for example and without limitation, multiple antenna groups, oneincluding 104 and 106, another including 108 and 110, and an additionalincluding 112 and 114. In FIG. 1, only two antennas are shown for eachantenna group, however, more or fewer antennas may be utilized for eachantenna group. Each group of antennas and/or the area in which they aredesigned to communicate is often referred to as a sector of the basestation 90. In the embodiment, antenna groups each are designed tocommunicate to UEs and/or access terminals in a sector, of the areascovered by the base station 90.

The base station 90 also includes a transceiver 91, a processor 92 and amemory 94. The transceiver 91 is coupled to the antenna groups describedabove. In one embodiment, the processor 92 is used to control thetransceiver 91 and retrieve and/or store data in the memory 94. Thememory 94 stores a neighbor list 80 that includes a list of neighborcell identifiers. That is the neighbor list 80 includes identifiers ofcells (e.g. macro, pico and/or femto) that are adjacent to and/oroverlap with the cell defined by the base station 90.

Similarly, the UE 120 includes an antenna 121, a transceiver 123, aprocessor 125 and a memory 127. The transceiver 123 is coupled to theantenna 121. In one embodiment, the processor 125 is used to control thetransceiver 123 and retrieve and/or store data in the memory 127. Thememory 127 stores a copy of the neighbor list 130 received from the basestation 90 or another base station (or access point).

As an example, in operation, the UE 120 is in communication withantennas 106 and 108, where antennas 106 and 108 transmit information,such as the neighbor list, to the UE 120 over forward link 126 andreceive information from the UE 120 over reverse link 124.

In communication over the forward link 126, the transmitting antennas ofthe base station 90 may utilize beamforming in order to improve thesignal-to-noise ratio of forward links for the UE 120. A base stationusing beamforming to transmit to UEs (or other access terminals)scattered randomly through its coverage causes less interference toaccess terminals in neighboring cells than an access point transmittingthrough a single antenna to all its access terminals.

One problem highlighted above is that according to various wirelessnetwork standards, such as UMTS, the size of the neighbor list isrestricted to a maximum size. That is, a base station or access pointcan only include a preset number of neighbor cell identifiers in theneighbor list at one time. The fixed size of a neighbor list provided bya standard may not reflect the realities of a wireless networkdeployment, especially for deployments including numerous femto cells(or pico cells) clustered in close proximity to one another. Inparticular, the number of cells in one area may exceed the maximum sizeof the neighbor list as specified in a standard governing thedeployment. Accordingly, as the concentration of macro cells, femtocells and/or pico cells in an area increases, there lies a challenge toidentify and communicate neighbor lists to user devices that reflect thearrangement of a particular portion of the deployment and the needs ofthe UEs.

Moreover, while an access point may have multiple neighbor cells, aparticular UE may only be able to request and receive communicationaccess from a subset of those neighbor cells. This could occur indeployments including various neighbor cells that each operate in one ofclosed, open or hybrid modes of operation. For example, some of theneighbor cells may only permit access to members of a closed subscribergroup and a particular UE may not be a member of that group.Alternatively, a neighbor cell may not have capacity to provide serviceto a particular UE.

Additionally, a particular subset of neighbor cells may be better suitedto provide service to a particular UE. For example, a mobile UE that istravelling relatively quickly may be better served by neighbor cell thatis a macro cell that provides service across a greater area than a femtocell in close proximity to the UE at the moment, thus reducing the needfor multiple hand-offs between neighbor cells as the UE travels across aparticular area.

Various systems, methods and apparatus described herein are configuredto provide a UE or a group of UEs a neighbor cell list that includesneighbor cell identifiers chosen from a candidate list. In oneembodiment, neighbor cell identifiers are chosen as an estimate of thoseneighbor cells that may better suit the needs of a particular UE or aparticular group of UEs. In another embodiment, neighbor cellidentifiers are chosen as an estimate of those neighbor cells that areclosest to a UE or group of UEs. In another embodiment, neighbor cellidentifiers are chosen as an estimate of those neighbor cells that arelikely to have the capacity to provide service to a particular UE orgroup of UEs. In another embodiment, neighbor cell identifiers arechosen as an estimate of those neighbor cells that are consideredrelatively more important in the deployment. Those skilled in the artwill also appreciate from the present disclosure that neighbor cellidentifiers can be chosen for a neighbor list based on various criteriawhich are too numerous to list exhaustively herein.

The neighbor cell identifiers chosen for a particular list can be chosenbased on at least one characteristic of each neighbor cell, without sucha characteristic being common to all neighbor cells on a candidate list.For example, such characteristics include, without limitation, a measureof the position of a wireless access point in the candidate list, ameasure of the type of cell provided by the wireless access point, ameasure of the size of the cell provided by the wireless access point, ameasure of the frequency of handoffs to a particular wireless accesspoint, an estimate of the probability that a wireless access point isavailable as a neighbor, an estimate of the relative importance of awireless access point, and a measure of the relative geographic positionof a wireless access point. Additionally and/or alternatively, suchcharacteristics also include, without limitation, a measure of the speedof a user device, a measure of the trajectory of a user device, ameasure of the present location of a user device, an indicatoridentifying an antenna or antenna group currently being used to servicea user device, an indicator of proximity of the user device to one ormore wireless access points, and reporting by a user device.

FIG. 2 is a flowchart illustrating a first method of forming a neighborcell list. In one example, the method is performed by the access pointcurrently servicing a particular UE. In another example, the method isperformed by another network node or even the core network at therequest of the access point currently servicing a particular UE. Asrepresented by block 2-1, the method includes sensing and/or receiving atrigger that initiates the formation and subsequent transmission of aneighbor list to one or more UEs. Examples of various types of triggersare discussed below with reference to FIGS. 3 and 7. As represented byblock 2-2, the method includes determining a candidate list of wirelessaccess points, including any combination of macro, pico, and femtonodes, in relatively close proximity to a particular access point thatis either forming the neighbor list or requesting formation of theneighbor list. In one embodiment an access point forms a neighbor listaccording to a method described herein. In another embodiment, an accesspoint requests another network element to form a neighbor list that theaccess point can then provide to one or more UEs. For example, withoutlimitation, in various embodiments a radio network controller ormobility management entity or any other network element is requested toform the neighbor list by an access point. In another embodiment,forming the candidate list includes at least one of requesting andreceiving at least one neighboring wireless access point identifier froma UE.

As represented by block 2-3, the method includes forming the neighborlist by selecting at least one neighbor cell identifier from thecandidate list. As represented by block 2-4, the method includestransmitting the formed neighbor list to one or more UEs. In oneembodiment the neighbor list is formed for use by a particular UE and istransmitted for the sole use of that particular UE. In anotherembodiment, the neighbor list is formed for use by a number of UEs.Those skilled in the art will also appreciate that if a neighbor listcannot be formed by selecting from the candidate list (e.g. thecandidate list is empty) a neighbor list will not be transmitted. In oneembodiment, the access point sends a message to one or more UE' sindicating that there are no neighbor cells.

FIG. 3 is a flowchart illustrating a second method of forming a neighborcell list. In one example, the method is performed by the access pointcurrently servicing a particular UE. In another example, the method isperformed by another network node or even the core network at therequest of the access point currently servicing a particular UE. Asrepresented by block 3-1, the method includes waiting for a random timebefore determining a candidate list of wireless access points andreceiving a trigger that interrupts the random wait time. If the randomwait time is interrupted by a received data trigger (RxT path from 3-1),as represented by block 3-2, the method includes determining whether thereceived data trigger is a request from one or more UEs or ameasurement.

If the received data trigger is a request (R path from 3-2), asrepresented by block 3-4, the method includes parsing the request todetermine if a UE has provided any information along with the requestthat can be used to influence the formation the neighbor list. Forexample, in one embodiment a UE can include in the request, one or moreneighbor cell identifiers that the UE cannot receive access from. Inanother example, a UE can provide information about which, if any,closed subscriber groups the UE does or does not belong to. Suchneighbor cell identifiers can then appropriately be left off or includedon the neighbor list transmitted to the UE.

On the other hand, if the received data trigger is a measurement (M pathfrom 3-2), as represented by block 3-5, the method includes creatingand/or retrieving a stored filter useful for forming the neighbor listfrom the measurement. For example, various measurements, withoutlimitation, include a measure of the position of a wireless access pointin the candidate list, a measure of the type of cell provided by thewireless access point, a measure of the size of the cell provided by thewireless access point, a measure of the frequency of handoffs to aparticular wireless access point, an estimate of the probability that awireless access point is available as a neighbor, an estimate of therelative importance of a wireless access point, and a measure of therelative geographic position of a wireless access point. Additionallyand/or alternatively, possible measurements also include, withoutlimitation, a measure of the speed of a user device, a measure of thetrajectory of a user device, a measure of the present location of a userdevice, an indicator identifying an antenna or antenna group currentlybeing used to service a user device, an indicator of proximity of theuser device to one or more wireless access points, and reporting by auser device. The filter can be configured to leave off or includeparticular neighbor cell identifiers on the neighbor cell list.

In one embodiment, the method includes actions represented by block 3-6after both the actions represented by blocks 3-4 and 3-5 discussedabove. Block 3-6 is discussed in greater detail below.

Referring again to block 3-1, if the random wait time is not interrupted(TO path from 3-1), the method includes bypassing portions of the methodrepresented by blocks 3-2, 3-4 and 3-5. As represented by block 3-6, themethod includes determining a candidate list of wireless access points,including any combination of macro, pico, and femto nodes, in relativelyclose proximity to a particular access point that is either forming theneighbor list or requesting formation of the neighbor list. Asrepresented by block 3-7, the method includes forming the neighbor listby selecting at least one neighbor cell identifier from the candidatelist. As represented by block 3-8, the method includes transmitting theformed neighbor list to one or more UEs.

FIG. 4 is a flowchart illustrating a third method of forming a neighborcell list. In one example, the method is performed by the access pointcurrently servicing a particular UE. In another example, the method isperformed by another network node or even the core network at therequest of the access point currently servicing a particular UE. Asrepresented by block 4-1, the method includes sensing and/or receiving atrigger that initiates the formation and subsequent transmission of aneighbor cell list to one or more UEs. As represented by block 4-2, themethod includes determining a candidate list of wireless access points,including any combination of macro, pico, and femto nodes, in relativelyclose proximity to a particular access point either forming the neighborlist or requesting formation of the neighbor list. As represented byblock 4-3, the method includes forming the neighbor list by selecting atleast one neighbor cell identifier from the candidate list. Asrepresented by block 4-4, the method includes transmitting the formedneighbor list to one or more UEs.

As represented by block 4-5, the method includes determining whether ornot the neighbor list transmitted to a UE was acceptable to the UE.Determining that a UE has not accepted the transmitted neighbor listincludes, without limitation, receiving a report that the UE has notaccepted the transmitted neighbor list. Determining that a UE hasaccepted the transmitted neighbor list includes, without limitation, atleast one of not receiving an indication to the contrary for a durationafter the neighbor list is transmitted, receiving a request to handoverservice to a UE to a neighboring wireless access point, receiving areport indicating that a UE has accepted the transmitted neighbor list

If the neighbor list is determined to have been acceptable to a UE (yespath from 4-5), as represented by block 4-6, the method includes waitinga random amount of time before iteratively determining a candidate list,as represented by block 4-2. On the other hand, if the neighbor list isdetermined to have not been acceptable to a UE (no path from 4-5), themethod includes iteratively restarting the actions represented by block4-1. Those skilled in the art will appreciate that in an alternativeembodiment the decision paths from block 4-5 can be the opposite of whatis illustrated in FIG. 4 and described above. For example, if theneighbor list is determined to have not been acceptable to a UE, analternative method includes iteratively determining a candidate list, asrepresented by block 4-2.

FIG. 5 is a flowchart illustrating a fourth method of forming a neighborcell list. In one example, the method is performed by the access pointcurrently servicing a particular UE. In another example, the method isperformed by another network node or even the core network at therequest of the access point currently servicing a particular UE. Asrepresented by block 5-1, the method includes determining a candidatelist of wireless access points, including any combination of macro,pico, and femto nodes, in relatively close proximity to a particularaccess point either forming the neighbor list or requesting formation ofthe neighbor list. As represented by block 5-2, the method includesretrieving a previously generated neighbor list. Without limitation, invarious embodiments, the previously generated neighbor list is retrievedfrom a non-transitory local memory, another wireless network element, anaccess point, a UE, a server, a host computer, and/or a cache on anelectronic device. Those skilled in the art will appreciate thatpreviously generated neighbor lists can be stored and retrieved from amultitude of places that are too numerous to exhaustively list herein.

As represented by block 5-3, the method includes deleting and/orexcluding one or more entries on the previously generated neighbor listfrom the candidate list, so as to prevent those one or more entries frombeing selected for a newly formed neighbor list. As represented by block5-4, the method includes forming the neighbor list by selecting at leastone neighbor cell identifier from the candidate list. As represented byblock 5-5, the method includes transmitting the formed neighbor list toone or more UEs.

FIG. 6 is a flowchart illustrating a fifth method of forming a neighborcell list. In one example, the method is performed by the access pointcurrently servicing a particular UE. In another example, the method isperformed by another network node or even the core network at therequest of the access point currently servicing a particular UE. Asrepresented by block 6-1, the method includes retrieving a previouslygenerated neighbor list. As represented by block 6-2, the methodincludes determining a candidate list of wireless access points,including any combination of macro, pico, and femto nodes, in relativelyclose proximity to a particular access point either forming the neighborlist or requesting formation of the neighbor list. As represented byblock 6-3, the method includes forming a new neighbor list by replacingat least one entry of the previously generated neighbor list with anentry on the candidate list. In one embodiment, the entry chosen fromthe candidate list is chosen at least because it is not the same as anyof the other entries on the previously generated neighbor list. Asrepresented by block 6-4, the method includes transmitting the formedneighbor list to one or more UEs.

FIG. 7 is a flowchart illustrating a sixth method of forming a neighborcell list. In one example, the method is performed by the access pointcurrently servicing a particular UE. In another example, the method isperformed by another network node or even the core network at therequest of the access point currently servicing a particular UE. Asrepresented by block 7-1, the method includes receiving data from a UE.As represented by block 7-2, the method includes determining whether thereceived data is a handover request from the UE or a report from the UE.If the received data is a handover request (HO path from 7-2), asrepresented by block 7-4, one embodiment of the method includes takingno further action. On the other hand, if the received data is a reportsent back from the UE (RB path from 7-2), as represented by block 7-3,the method includes determining whether or not a previously transmittedneighbor list was accepted to the UE by parsing the report sent backfrom the UE.

If it is determined that the previously transmitted neighbor list wasacceptable (yes path from 7-3), as represented by block 7-4, oneembodiment of the method includes taking no further action, as describedabove. On the other hand, if it is determined that the previouslytransmitted neighbor list was not acceptable (no path from 7-3), asrepresented by block 7-5, the method includes reforming a neighbor list.The neighbor list can be reformed according to any of the various methoddescribed above and/or various combinations of actions described above.As represented by block 7-6, the method includes transmitting the formedneighbor list to one or more UEs.

FIG. 8 is a flowchart illustrating a seventh method of forming aneighbor cell list. In one example, the method is performed by theaccess point currently servicing a particular UE. In another example,the method is performed by another network node or even the core networkat the request of the access point currently servicing a particular UE.As represented by block 8-1, the method includes determining a candidatelist of wireless access points, including any combination of macro,pico, and femto nodes, in relatively close proximity to a particularaccess point either forming the neighbor list or requesting formation ofthe neighbor list. As represented by block 8-2, the method includesselecting a first sub-list of neighbor cell identifiers from thecandidate list. Without limitation, the first sub-list includes wirelessaccess points selected based on at least one of a measure of theposition of a wireless access point in the candidate list, a measure ofthe type of cell provided by the wireless access point, a measure of thesize of the cell provided by the wireless access point, a measure of thefrequency of handoffs to a wireless access point, a measure of theprobability that a wireless access point is available as a neighbor, ameasure of the relative importance of a wireless access point, and ameasure of the relative geographic position of a wireless access point.

As represented by block 8-3, the method includes selecting at least asecond sub-list of neighbor cell identifiers from the candidate list. Asrepresented by block 8-4, the method includes combining the firstsub-list and at least the second sub-list to form a complete neighborlist. As represented by block 8-5, the method includes transmitting theformed neighbor list to one or more UEs.

FIG. 9 is a simplified diagram of a wireless communication system 900,configured to support a number of users, in which the teachings hereinmay be implemented. The system 900 provides communication for multiplecells 902, such as, for example, macro cells 902A-902G, with each cellbeing serviced by a corresponding access point 904 (e.g., access points904A-904G). Access terminals 906 (e.g., access terminals 906A-906L) maybe dispersed at various locations throughout the system over time. Eachaccess terminal 906 may communicate with one or more access points 904on a forward link (FL) and/or a reverse link (RL) at a given moment,depending upon whether the access terminal 906 is active and whether itis in soft handoff, for example. The wireless communication system 900may provide service over a large geographic region. For example, macrocells 902A-902G may cover a few blocks in a densely populated urbanneighborhood or several miles in rural environment.

FIG. 10 is a simplified diagram of an example communication system 1000where one or more femto nodes are deployed within a network environment.Specifically, the system 1000 includes multiple femto nodes 1010 (e.g.,femto nodes 1010A and 1010B) installed in a relatively small scalenetwork environment (e.g., in one or more user residences 1030). Eachfemto node 1010 may be coupled to a wide area network 1040 (e.g., theInternet) and a mobile operator core network 1050 via a DSL router, acable modem, a wireless link, or other connectivity means (not shown).As will be discussed below, each femto node 1010 may be configured toserve associated access terminals 1020 (e.g., access terminal 1020A)and, optionally, alien access terminals 1020 (e.g., access terminal1020B). In other words, access to femto nodes 1010 may be restrictedwhereby a given access terminal 1020 may be served by a set ofdesignated (e.g., home) femto node(s) 1010 but may not be served by anynon-designated femto nodes 1010 (e.g., a neighbor's femto node 1010).

FIG. 11 is a simplified diagram illustrating an example of a coveragemap 1100 where several tracking areas 1102 (or routing areas or locationareas) are defined, each of which includes several macro coverage areas1104. Here, areas of coverage associated with tracking areas 1102A,1102B, and 1102C are delineated by the wide lines and the macro coverageareas 1104 are represented by the hexagons. The tracking areas 1102 alsoinclude femto coverage areas 1106. In this example, each of the femtocoverage areas 1106 (e.g., femto coverage area 1106C) is depicted withina macro coverage area 1104 (e.g., macro coverage area 1104B). It shouldbe appreciated, however, that a femto coverage area 1106 may not lieentirely within a macro coverage area 1104. In practice, a large numberof femto coverage areas 1106 may be defined with a given tracking area1102 or macro coverage area 1104. Also, one or more pico coverage areas(not shown) may be defined within a given tracking area 1102 or macrocoverage area 1104.

Referring again to FIG. 10, the owner of a femto node 1010 may subscribeto mobile service, such as, for example, 3G mobile service, offeredthrough the mobile operator core network 1050. In addition, an accessterminal 1020 may be capable of operating both in macro environments andin smaller scale (e.g., residential) network environments. In otherwords, depending on the current location of the access terminal 1020,the access terminal 1020 may be served by a macro cell access point 1060associated with the mobile operator core network 1050 or by any one of aset of femto nodes 1010 (e.g., the femto nodes 1010A and 1010B thatreside within a corresponding user residence 1030). For example, when asubscriber is outside his home, he is served by a standard macro accesspoint (e.g., access point 1060) and when the subscriber is at home, heis served by a femto node (e.g., node 1010A). Here, it should beappreciated that a femto node 1010 may be backward compatible withexisting access terminals 1020.

A femto node 1010 may be deployed on a single frequency or, in thealternative, on multiple frequencies. Depending on the particularconfiguration, the single frequency or one or more of the multiplefrequencies may overlap with one or more frequencies used by a macroaccess point (e.g., access point 1060).

In some aspects, an access terminal 1020 may be configured to connect toa preferred femto node (e.g., the home femto node of the access terminal1020) whenever such connectivity is possible. For example, whenever theaccess terminal 1020 is within the user's residence 1030, it may bedesired that the access terminal 1020 communicate only with the homefemto node 1010.

In some aspects, if the access terminal 1020 operates within the macrocellular network 1050 but is not residing on its most preferred network(e.g., as defined in a preferred roaming list), the access terminal 1020may continue to search for the most preferred network (e.g., thepreferred femto node 1010) using a Better System Reselection (BSR),which may involve a periodic scanning of available systems to determinewhether better systems are currently available, and subsequent effortsto associate with such preferred systems. With the acquisition entry,the access terminal 1020 may limit the search for specific band andchannel. For example, the search for the most preferred system may berepeated periodically. Upon discovery of a preferred femto node 1010,the access terminal 1020 selects the femto node 1010 for camping withinits coverage area.

A femto node may be restricted in some aspects. For example, a givenfemto node may only provide certain services to certain accessterminals. In deployments with so-called restricted (or closed)association, a given access terminal may only be served by the macrocell mobile network and a defined set of femto nodes (e.g., the femtonodes 1010 that reside within the corresponding user residence 1030). Insome implementations, a node may be restricted to not provide, for atleast one node, at least one of: signaling, data access, registration,paging, or service.

In some aspects, a restricted femto node (which may also be referred toas a Closed Subscriber Group Home NodeB) is one that provides service toa restricted provisioned set of access terminals. This set may betemporarily or permanently extended as useful. In some aspects, a closedsubscriber group (CSG) may be defined as the set of access points (e.g.,femto nodes) that share a common access control list of accessterminals. A restricted access point may include a CSG that allowsmultiple access terminals to connect to it. A single access terminal mayhave the ability connect to multiple restricted access points. A channelon which all femto nodes (or all restricted femto nodes) in a regionoperate may be referred to as a femto channel.

Various relationships may thus exist between a given femto node and agiven access terminal. For example, from the perspective of an accessterminal, an open femto node may refer to a femto node with norestricted association (e.g., the femto node allows access to any accessterminal). A restricted femto node may refer to a femto node that isrestricted in some manner (e.g., restricted for association and/orregistration). A home femto node may refer to a femto node on which theaccess terminal is authorized to access and operate on (e.g., permanentaccess is provided for a defined set of one or more access terminals). Aguest femto node may refer to a femto node on which an access terminalis temporarily authorized to access or operate on. An alien femto nodemay refer to a femto node on which the access terminal is not authorizedto access or operate on, except for perhaps emergency situations (e.g.,911 calls).

From a restricted femto node perspective, a home access terminal mayrefer to an access terminal that is authorized to access the restrictedfemto node (e.g., the access terminal has permanent access to the femtonode). A guest access terminal may refer to an access terminal withtemporary access to the restricted femto node (e.g., limited based ondeadline, time of use, bytes, connection count, or some other criterionor criteria). An alien access terminal may refer to an access terminalthat does not have permission to access the restricted femto node,except for perhaps emergency situations, for example, such as 911 calls(e.g., an access terminal that does not have the credentials orpermission to register with the restricted femto node).

For convenience, the disclosure herein describes various functionalityin the context of a femto node. It should be appreciated, however, thata pico node may provide the same or similar functionality for a largercoverage area. For example, a pico node may be restricted, a home piconode may be defined for a given access terminal, and so on.

A wireless multiple-access communication system may simultaneouslysupport communication for multiple wireless access terminals. Asmentioned above, each terminal may communicate with one or more basestations via transmissions on the forward and reverse links. The forwardlink (or downlink) refers to the communication link from the basestations to the terminals, and the reverse link (or uplink) refers tothe communication link from the terminals to the base stations. Thiscommunication link may be established via a single-in-single-out system,a multiple-in-multiple-out (MIMO) system, or some other type of system.

A MIMO system employs multiple (N_(T)) transmit antennas and multiple(N_(R)) receive antennas for data transmission. A MIMO channel formed bythe N_(T) transmit and N_(R) receive antennas may be decomposed intoN_(s) independent channels, which are also referred to as spatialchannels, where N_(S)≦min{N_(T), N_(R)}. Each of the N_(S) independentchannels corresponds to a dimension. The MIMO system may provideimproved performance (e.g., higher throughput and/or greaterreliability) if the additional dimensionalities created by the multipletransmit and receive antennas are utilized.

A MIMO system may support time division duplex (TDD) and frequencydivision duplex (FDD). In a TDD system, the forward and reverse linktransmissions are on the same frequency region so that the reciprocityprinciple allows the estimation of the forward link channel from thereverse link channel. This enables the access point to extract transmitbeam-forming gain on the forward link when multiple antennas areavailable at the access point.

The teachings herein may be incorporated into a node (e.g., a device)employing various components for communicating with at least one othernode. FIG. 12 depicts several sample components that may be employed tofacilitate communication between nodes. Specifically, FIG. 12 is asimplified block diagram of a first wireless device 1210 (e.g., anaccess point) and a second wireless device 1250 (e.g., an accessterminal) of a MIMO system 1200. At the first device 1210, traffic datafor a number of data streams is provided from a data source 1212 to atransmit (TX) data processor 1214.

In some aspects, each data stream is transmitted over a respectivetransmit antenna. The TX data processor 1214 formats, codes, andinterleaves the traffic data for each data stream based on a particularcoding scheme selected for that data stream to provide coded data.

The coded data for each data stream may be multiplexed with pilot datausing OFDM techniques. The pilot data is typically a known data patternthat is processed in a known manner and may be used at the receiversystem to estimate the channel response. The multiplexed pilot and codeddata for each data stream is then modulated (i.e., symbol mapped) basedon a particular modulation scheme (e.g., BPSK, QSPK, M-PSK, or M-QAM)selected for that data stream to provide modulation symbols. The datarate, coding, and modulation for each data stream may be determined byinstructions performed by a processor 1230. A data memory 1232 may storeprogram code, data, and other information used by the processor 1230 orother components of the device 1210.

The modulation symbols for all data streams are then provided to a TXMIMO processor 1220, which may further process the modulation symbols(e.g., for OFDM). The TX MIMO processor 1220 then provides N_(T)modulation symbol streams to N_(T) transceivers (XCVR) 1222A through1222T. In some aspects, the TX MIMO processor 1220 applies beam-formingweights to the symbols of the data streams and to the antenna from whichthe symbol is being transmitted.

Each transceiver 1222 receives and processes a respective symbol streamto provide one or more analog signals, and further conditions (e.g.,amplifies, filters, and upconverts) the analog signals to provide amodulated signal suitable for transmission over the MIMO channel. N_(T)modulated signals from transceivers 1222A through 1222T are thentransmitted from N_(T) antennas 1224A through 1224T, respectively.

At the second device 1250, the transmitted modulated signals arereceived by N_(R) antennas 1252A through 1252R and the received signalfrom each antenna 1252 is provided to a respective transceiver (XCVR)1254A through 1254R. Each transceiver 1254 conditions (e.g., filters,amplifies, and downconverts) a respective received signal, digitizes theconditioned signal to provide samples, and further processes the samplesto provide a corresponding “received” symbol stream.

A receive (RX) data processor 1260 then receives and processes the N_(R)received symbol streams from N_(R) transceivers 1254 based on aparticular receiver processing technique to provide N_(T) “detected”symbol streams. The RX data processor 1260 then demodulates,deinterleaves, and decodes each detected symbol stream to recover thetraffic data for the data stream. The processing by the RX dataprocessor 1260 is complementary to that performed by the TX MIMOprocessor 1220 and the TX data processor 1214 at the device 1210.

A processor 1270 periodically determines which pre-coding matrix to use(discussed below). The processor 1270 formulates a reverse link messagecomprising a matrix index portion and a rank value portion. A datamemory 1272 may store program code, data, and other information used bythe processor 1270 or other components of the second device 1250.

The reverse link message may comprise various types of informationregarding the communication link and/or the received data stream. Thereverse link message is then processed by a TX data processor 1238,which also receives traffic data for a number of data streams from adata source 1236, modulated by a modulator 1280, conditioned by thetransceivers 1254A through 1254R, and transmitted back to the device1210.

At the device 1210, the modulated signals from the second device 1250are received by the antennas 1224, conditioned by the transceivers 1222,demodulated by a demodulator (DEMOD) 1240, and processed by a RX dataprocessor 1242 to extract the reverse link message transmitted by thesecond device 1250. The processor 1230 then determines which pre-codingmatrix to use for determining the beam-forming weights then processesthe extracted message.

FIG. 12 also illustrates that the communication components may includeone or more components that perform access control operations as taughtherein. For example, an access control component 1290 may cooperate withthe processor 1230 and/or other components of the device 1210 tosend/receive signals to/from another device (e.g., device 1250) astaught herein. Similarly, an access control component 1292 may cooperatewith the processor 1270 and/or other components of the device 1250 tosend/receive signals to/from another device (e.g., device 1210). Itshould be appreciated that for each device 1210 and 1250 thefunctionality of two or more of the described components may be providedby a single component. For example, a single processing component mayprovide the functionality of the access control component 1290 and theprocessor 1230 and a single processing component may provide thefunctionality of the access control component 1292 and the processor1270.

The teachings herein may be incorporated into (e.g., implemented withinor performed by) a variety of apparatuses (e.g., nodes). In someaspects, a node (e.g., a wireless node) implemented in accordance withthe teachings herein may comprise an access point or an access terminal.

For example, an access terminal may comprise, be implemented as, orknown as user equipment, a subscriber station, a subscriber unit, amobile station, a mobile, a mobile node, a remote station, a remoteterminal, a user terminal, a user agent, a user device, or some otherterminology. In some implementations an access terminal may comprise acellular telephone, a cordless telephone, a session initiation protocol(SIP) phone, a wireless local loop (WLL) station, a personal digitalassistant (PDA), a handheld device having wireless connectioncapability, or some other suitable processing device connected to awireless modem. Accordingly, one or more aspects taught herein may beincorporated into a phone (e.g., a cellular phone or smart phone), acomputer (e.g., a laptop), a portable communication device, a portablecomputing device (e.g., a personal data assistant), an entertainmentdevice (e.g., a music device, a video device, or a satellite radio), aglobal positioning system device, or any other suitable device that isconfigured to communicate via a wireless medium.

An access point may comprise, be implemented as, or known as a NodeB, aneNodeB, a radio network controller (RNC), a base station (BS), a radiobase station (RBS), a base station controller (BSC), a base transceiverstation (BTS), a transceiver function (TF), a radio transceiver, a radiorouter, a basic service set (BSS), an extended service set (ESS), orsome other similar terminology.

In some aspects a node (e.g., an access point) may comprise an accessnode for a communication system. Such an access node may provide, forexample, connectivity for or to a network (e.g., a wide area networksuch as the Internet or a cellular network) via a wired or wirelesscommunication link to the network. Accordingly, an access node mayenable another node (e.g., an access terminal) to access a network orsome other functionality. In addition, it should be appreciated that oneor both of the nodes may be portable or, in some cases, relativelynon-portable.

Also, it should be appreciated that a wireless node may be capable oftransmitting and/or receiving information in a non-wireless manner(e.g., via a wired connection). Thus, a receiver and a transmitter asdiscussed herein may include appropriate communication interfacecomponents (e.g., electrical or optical interface components) tocommunicate via a non-wireless medium.

A wireless node may communicate via one or more wireless communicationlinks that are based on or otherwise support any suitable wirelesscommunication technology. For example, in some aspects a wireless nodemay associate with a network. In some aspects the network may comprise alocal area network or a wide area network. A wireless device may supportor otherwise use one or more of a variety of wireless communicationtechnologies, protocols, or standards such as those discussed herein(e.g., CDMA, TDMA, OFDM, OFDMA, WiMAX, Wi-Fi, and so on). Similarly, awireless node may support or otherwise use one or more of a variety ofcorresponding modulation or multiplexing schemes. A wireless node maythus include appropriate components (e.g., air interfaces) to establishand communicate via one or more wireless communication links using theabove or other wireless communication technologies. For example, awireless node may comprise a wireless transceiver with associatedtransmitter and receiver components that may include various components(e.g., signal generators and signal processors) that facilitatecommunication over a wireless medium.

The components described herein may be implemented in a variety of ways.Referring to FIGS. 13-23, apparatuses 1300, 1400, 1500, 1600, 1700,1800, 1900, 2000, 2100, 2200, and 2300 are represented as a series ofinterrelated functional blocks. In some aspects the functionality ofthese blocks may be implemented as a processing system including one ormore processor components. In some aspects the functionality of theseblocks may be implemented using, for example, at least a portion of oneor more integrated circuits (e.g., an ASIC). As discussed herein, anintegrated circuit may include a processor, software, other relatedcomponents, or some combination thereof. The functionality of theseblocks also may be implemented in some other manner as taught herein. Insome aspects one or more of the dashed blocks in FIGS. 13-23 areoptional.

The apparatuses 1300, 1400, 1500, 1600, 1700, 1800, 1900, 2000, 2100,2200, and 2300 may include one or more modules that may perform one ormore of the functions described above with regard to various figures.For example, a receiving/sending means 1302 may correspond to, forexample, a communication controller as discussed herein. An identifierdetermining means 1304 may correspond to, for example, an accesscontroller as discussed herein. An allowed service determining means1306 may correspond to, for example, an access controller as discussedherein. A receiving means 1402 may correspond to, for example, acommunication controller as discussed herein. A sending means 1404 maycorrespond to, for example, an access controller as discussed herein. Anidentifier determining means 1406 may correspond to, for example, anaccess controller as discussed herein. A sending means 1502 maycorrespond to, for example, an access controller as discussed herein. Areceiving means 1504 may correspond to, for example, a communicationcontroller as discussed herein. An allowed service determining means1506 may correspond to, for example, an access controller as discussedherein. A configuring means 1602 may correspond to, for example, aprovisioning controller as discussed herein. An obtaining means 1604 maycorrespond to, for example, an access controller as discussed herein. Areceiving means 1606 may correspond to, for example, a communicationcontroller as discussed herein. A determining means 1608 may correspondto, for example, an access controller as discussed herein. An identifierdetermining means 1702 may correspond to, for example, an provisioningcontroller as discussed herein. A sending means 1704 may correspond to,for example, a communication controller as discussed herein. Anassigning means 1706 may correspond to, for example, a provisioningcontroller as discussed herein. A receiving means 1802 may correspondto, for example, a provisioning controller as discussed herein. Atransmitting means 1804 may correspond to, for example, a communicationcontroller as discussed herein. An identifier determining means 1902 maycorrespond to, for example, a provisioning controller as discussedherein. A sending means 1904 may correspond to, for example, acommunication controller as discussed herein. A receiving means 2002 maycorrespond to, for example, a communication controller as discussedherein. An access enablement determining means 2004 may correspond to,for example, an access controller as discussed herein. Aconfiguration-based determining means 2006 may correspond to, forexample, an access controller as discussed herein. A list maintainingmeans 2008 may correspond to, for example, an access controller asdiscussed herein. A configuring means 2102 may correspond to, forexample, a provisioning controller as discussed herein. A transmittingmeans 2104 may correspond to, for example, a communication controller asdiscussed herein. A receiving means 2106 may correspond to, for example,a communication controller as discussed herein. A sending means 2108 maycorrespond to, for example, a provisioning controller as discussedherein. A defining means 2110 may correspond to, for example, aprovisioning controller as discussed herein. A monitoring means 2202 maycorrespond to, for example, a receiver as discussed herein. A beaconreceiving means 2204 may correspond to, for example, a receiver asdiscussed herein. A sending means 2206 may correspond to, for example, acommunication controller as discussed herein. A roaming list receivingmeans 2208 may correspond to, for example, a provisioning controller asdiscussed herein. A configuring means 2302 may correspond to, forexample, a provisioning controller as discussed herein. A beaconreceiving means 2304 may correspond to, for example, a receiver asdiscussed herein. A sending means 2306 may correspond to, for example, acommunication controller as discussed herein. An authorization receivingmeans 2308 may correspond to, for example, an access controller asdiscussed herein. A prompting means 2310 may correspond to, for example,an access controller as discussed herein. A displaying means 2312 maycorrespond to, for example, an access controller as discussed herein.

It should be understood that any reference to an element herein using adesignation such as “first,” “second,” and so forth does not generallylimit the quantity or order of those elements. Rather, thesedesignations may be used herein as a convenient method of distinguishingbetween two or more elements or instances of an element. Thus, areference to first and second elements does not mean that only twoelements may be employed there or that the first element must precedethe second element in some manner. Also, unless stated otherwise a setof elements may comprise one or more elements.

Those of skill in the art would understand that information and signalsmay be represented using any of a variety of different technologies andtechniques. For example, data, instructions, commands, information,signals, bits, symbols, and chips that may be referenced throughout theabove description may be represented by voltages, currents,electromagnetic waves, magnetic fields or particles, optical fields orparticles, or any combination thereof.

Those of skill would further appreciate that any of the variousillustrative logical blocks, modules, processors, means, circuits, andalgorithm steps described in connection with the aspects disclosedherein may be implemented as electronic hardware (e.g., a digitalimplementation, an analog implementation, or a combination of the two,which may be designed using source coding or some other technique),various forms of program or design code incorporating instructions(which may be referred to herein, for convenience, as “software” or a“software module), or combinations of both. To clearly illustrate thisinterchangeability of hardware and software, various illustrativecomponents, blocks, modules, circuits, and steps have been describedabove generally in terms of their functionality. Whether suchfunctionality is implemented as hardware or software depends upon theparticular application and design constraints imposed on the overallsystem. Skilled artisans may implement the described functionality invarying ways for each particular application, but such implementationdecisions should not be interpreted as causing a departure from thescope of the present disclosure.

The various illustrative logical blocks, modules, and circuits describedin connection with the aspects disclosed herein may be implementedwithin or performed by an integrated circuit (IC), an access terminal,or an access point. The IC may comprise a general purpose processor, adigital signal processor (DSP), an application specific integratedcircuit (ASIC), a field programmable gate array (FPGA) or otherprogrammable logic device, discrete gate or transistor logic, discretehardware components, electrical components, optical components,mechanical components, or any combination thereof designed to performthe functions described herein, and may execute codes or instructionsthat reside within the IC, outside of the IC, or both. A general purposeprocessor may be a microprocessor, but in the alternative, the processormay be any conventional processor, controller, microcontroller, or statemachine. A processor may also be implemented as a combination ofcomputing devices, e.g., a combination of a DSP and a microprocessor, aplurality of microprocessors, one or more microprocessors in conjunctionwith a DSP core, or any other such configuration.

It is understood that any specific order or hierarchy of steps in anydisclosed process is an example of a sample approach. Based upon designpreferences, it is understood that the specific order or hierarchy ofsteps in the processes may be rearranged while remaining within thescope of the present disclosure. The accompanying method claims presentelements of the various steps in a sample order, and are not meant to belimited to the specific order or hierarchy presented.

The functions described may be implemented in hardware, software,firmware, or any combination thereof. If implemented in software, thefunctions may be stored on or transmitted over as one or moreinstructions or code on a computer-readable medium. Computer-readablemedia includes both computer storage media and communication mediaincluding any medium that facilitates transfer of a computer programfrom one place to another. A storage media may be any available mediathat can be accessed by a computer. By way of example, and notlimitation, such computer-readable media can comprise RAM, ROM, EEPROM,CD-ROM or other optical disk storage, magnetic disk storage or othermagnetic storage devices, or any other medium that can be used to carryor store desired program code in the form of instructions or datastructures and that can be accessed by a computer. Also, any connectionis properly termed a computer-readable medium. For example, if thesoftware is transmitted from a website, server, or other remote sourceusing a coaxial cable, fiber optic cable, twisted pair, digitalsubscriber line (DSL), or wireless technologies such as infrared, radio,and microwave, then the coaxial cable, fiber optic cable, twisted pair,DSL, or wireless technologies such as infrared, radio, and microwave areincluded in the definition of medium. Disk and disc, as used herein,includes compact disc (CD), laser disc, optical disc, digital versatiledisc (DVD), floppy disk and blu-ray disc where disks usually reproducedata magnetically, while discs reproduce data optically with lasers.Combinations of the above should also be included within the scope ofcomputer-readable media. In summary, it should be appreciated that acomputer-readable medium may be implemented in any suitablecomputer-program product.

The above description is provided to enable any person skilled in theart to make or use embodiments within the scope of the appended claims.Various modifications to these aspects will be readily apparent to thoseskilled in the art, and the generic principles defined herein may beapplied to other aspects without departing from the scope of thedisclosure. Thus, the present disclosure is not intended to be limitedto the aspects shown herein but is to be accorded the widest scopeconsistent with the principles and novel features disclosed herein.

What is claimed is:
 1. A method of forming a list of neighboringwireless access points, the method comprising: determining a candidatelist, the candidate list including a plurality of neighboring wirelessaccess points, wherein each of the plurality of neighboring wirelessaccess points has at least one characteristic by which that particularneighboring wireless access point can be selected; and selecting, by aprocessor, at least one neighboring wireless access point from thecandidate list to form a neighbor list based on reporting received froma plurality of user devices in communication with the neighboringwireless access point, the neighbor list including a subset of theplurality of neighboring wireless access points included in thecandidate list, wherein the reporting corresponds to whether each of theplurality of user device accepted a previously transmitted neighborlist, wherein the plurality of neighboring wireless access pointsincludes one or more base stations providing macro cells, one or morefemto nodes providing cells smaller than macro cells, one or morewireless access points providing adjacent cells to one another, one ormore wireless access points providing overlapping cells in combinationwith other wireless access points, or a combination thereof.
 2. Themethod of claim 1, wherein determining the candidate list comprises oneor both of reading and receiving the candidate list from one or more ofa computer readable memory, a management node, a network, and a radionetwork controller.
 3. The method of claim 1, wherein determining thecandidate list comprises one or both of requesting and receiving atleast one neighboring wireless access point identifier from an accessterminal.
 4. The method of claim 1, further comprising sensing a triggerthat initiates forming a list of neighboring wireless access points. 5.The method of claim 4, wherein the trigger includes one or more of ameasure of the time elapsed since a previous neighbor list was formed, areceived request from a user device for a new neighbor list, and ameasurement based on the motion of a user device.
 6. The method of claim1, further comprising: transmitting the neighbor list to at least oneuser device; determining whether or not the at least one user device hasaccepted the transmitted neighbor list; and forming a new neighbor listwhen a determination is made that the at least one user device has notaccepted the transmitted neighbor list.
 7. The method of claim 6,wherein forming the new neighbor list comprises: deleting the wirelessaccess points in a previously formed neighbor list from the candidatelist to produce an updated candidate list; and selecting wireless accesspoints from the updated candidate list to form the new neighbor list. 8.The method of claim 6, wherein determining that the at least one userdevice has not accepted the transmitted neighbor list includes receivinga report that the at least one user device has not accepted thetransmitted neighbor list.
 9. The method of claim 6, wherein determiningthat the at least one user device has accepted the transmitted neighborlist includes one or more of not receiving an indication to the contraryfor a duration after the neighbor list is transmitted, receiving arequest to handover service to the at least one user device to aneighboring wireless access point, and receiving a report indicatingthat the at least one user device has accepted the transmitted neighborlist.
 10. The method of claim 1, wherein the at least one characteristicincludes one or more of a measure of the position of a wireless accesspoint in the candidate list, a measure of the type of cell provided bythe wireless access point, a measure of the size of the cell provided bythe wireless access point, a measure of the frequency of handoffs to aparticular wireless access point, an estimate of the probability that awireless access point is available as a neighbor, an estimate of therelative importance of a wireless access point, and a measure of therelative geographic position of a wireless access point.
 11. The methodof claim 1, wherein wireless access points are selected for the neighborlist based on one or more of a measure of the speed of a user device, ameasure of the trajectory of a user device, a measure of the presentlocation of a user device, an indicator identifying an antenna orantenna group currently being used to service a user device, anindicator of proximity of the user device to one or more wireless accesspoints, and reporting by a user device.
 12. The method of claim 1,further comprising selecting wireless access points for the neighborlist by: selecting a first sub-list of preferred wireless access pointsfrom the candidate list; and selecting at least a second sub-list ofwireless access points to complete the neighbor list.
 13. The method ofclaim 12, wherein the first sub-list includes wireless access pointsselected based on one or more of a measure of the position of a wirelessaccess point in the candidate list, a measure of the type of cellprovided by the wireless access point, a measure of the size of the cellprovided by the wireless access point, a measure of the frequency ofhandoffs to a wireless access point, a measure of the probability that awireless access point is available as a neighbor, a measure of therelative importance of a wireless access point, and a measure of therelative geographic position of a wireless access point.
 14. The methodof claim 1, further comprising: transmitting the neighbor list to atleast one user device; estimating whether or not the at least one userdevice has had an opportunity to accept the transmitted neighbor list;and forming a new neighbor list when it is estimated that the at leastone user device has not accepted the transmitted neighbor list.
 15. Awireless access point comprising: means for determining a candidatelist, the candidate list including a plurality of neighboring wirelessaccess points, wherein each of the plurality of neighboring wirelessaccess points has at least one characteristic by which that particularneighboring wireless access point can be selected; and means forselecting at least one neighboring wireless access point from thecandidate list to form a neighbor list based on reporting received froma plurality of user devices in communication with the neighboringwireless access point, the neighbor list including a subset of theplurality of neighboring wireless access points included in thecandidate list, wherein the reporting corresponds to whether each of theplurality of user devices accepted a previously transmitted neighborlist, wherein the plurality of neighboring wireless access pointsincludes one or more base stations providing macro cells, one or morefemto nodes providing cells smaller than macro cells, one or morewireless access points providing adjacent cells to one another, one ormore wireless access points providing overlapping cells in combinationwith other wireless access points, or a combination thereof.
 16. Anon-transitory computer readable memory comprising: code for determininga candidate list, the candidate list including a plurality ofneighboring wireless access points, wherein each of the plurality ofneighboring wireless access points has at least one characteristic bywhich that particular neighboring wireless access point can be selected;and code for selecting at least one neighboring wireless access pointfrom the candidate list to form a neighbor list based on reportingreceived from a plurality of user devices in communication with theneighboring wireless access point, the neighbor list including a subsetof the plurality of neighboring wireless access points included in thecandidate list, wherein the reporting corresponds to whether each of theplurality of user devices accepted a previously transmitted neighborlist, wherein the plurality of neighboring wireless access pointsincludes one or more base stations providing macro cells, one or morefemto nodes providing cells smaller than macro cells, one or morewireless access points providing adjacent cells to one another, one ormore wireless access points providing overlapping cells in combinationwith other wireless access points, or a combination thereof.
 17. Awireless access point comprising: a memory storing executableinstructions; and a processor in communication with the memory, whereinthe processor is configured to execute the instructions to: determine acandidate list, the candidate list including a plurality of neighboringwireless access points, wherein each of the plurality of neighboringwireless access points has at least one characteristic by which thatparticular neighboring wireless access point can be selected; and selectat least one neighboring wireless access point from the candidate listto form a neighbor list based on reporting received from a plurality ofuser devices in communication with the neighboring wireless accesspoint, the neighbor list including a subset of the plurality ofneighboring wireless access points included in the candidate list,wherein the reporting corresponds to whether each of the plurality ofuser devices accepted a previously transmitted neighbor list, whereinthe plurality of neighboring wireless access points includes one or morebase stations providing macro cells, one or more femto nodes providingcells smaller than macro cells, one or more wireless access pointsproviding adjacent cells to one another, one or more wireless accesspoints providing overlapping cells in combination with other wirelessaccess points, or a combination thereof.
 18. The wireless access pointof claim 17, wherein the instructions to determine the candidate listcomprise one or both of instructions to read and instructions to receivethe candidate list from one or more of a computer readable memory, amanagement node, a network, and a radio network controller.
 19. Thewireless access point of claim 17, wherein the instructions to determinethe candidate list comprise one or both of instructions to request andinstructions to receive at least one neighboring wireless access pointidentifier from an access terminal.
 20. The wireless access point ofclaim 17, wherein the processor is further configured to executeinstructions to sense a trigger that initiates forming a list ofneighboring wireless access points.
 21. The wireless access point ofclaim 20, wherein the trigger includes one or more of a measure of thetime elapsed since a previous neighbor list was formed, a receivedrequest from a user device for a new neighbor list, and a measurementbased on the motion of a user device.
 22. The wireless access point ofclaim 17, wherein the processor is further configured to executeinstructions to: transmit the neighbor list to at least one user device;determine whether or not the at least one user device has accepted thetransmitted neighbor list; and form a new neighbor list when it isdetermined that the at least one user device has not accepted thetransmitted neighbor list.
 23. The wireless access point of claim 22,wherein the instructions to determine that the at least one user devicehas not accepted the transmitted neighbor list includes instructions toreceive a report that the at least one user device has not accepted thetransmitted neighbor list.
 24. The wireless access point of claim 22,wherein the instructions to determine that the at least one user devicehas accepted the transmitted neighbor list includes one or more ofinstructions to not receive an indication to the contrary for a durationafter the neighbor list is transmitted, instructions to receive arequest to handover service to the at least one user device to aneighboring wireless access point, instructions to receive a reportindicating that the at least one user device has accepted thetransmitted neighbor list.
 25. The wireless access point of claim 17,wherein the at least one characteristic includes one or more of ameasure of the position of a wireless access point in the candidatelist, a measure of the type of cell provided by the wireless accesspoint, a measure of the size of the cell provided by the wireless accesspoint, a measure of the frequency of handoffs to a particular wirelessaccess point, an estimate of the probability that a wireless accesspoint is available as a neighbor, an estimate of the relative importanceof a wireless access point, and a measure of the relative geographicposition of a wireless access point.
 26. The wireless access point ofclaim 17, wherein wireless access points are selected for the neighborlist based on one or more of a measure of the speed of a user device, ameasure of the trajectory of a user device, a measure of the presentlocation of a user device, an indicator identifying an antenna orantenna group currently being used to service a user device, anindicator of proximity of the user device to one or more wireless accesspoints, and reporting by a user device.
 27. The wireless access point ofclaim 17, wherein the processor is further configured to executeinstructions to: select a first sub-list of preferred wireless accesspoints from the candidate list; and select at least a second sub-list ofwireless access points to complete the neighbor list.
 28. The wirelessaccess point of claim 17 wherein the processor is further configured toexecute instructions to: transmit the neighbor list to at least one userdevice; estimate whether or not the at least one user device has had anopportunity to accept the transmitted neighbor list; and form a newneighbor list when it is estimated that the at least one user device hasnot accepted the transmitted neighbor list.